diff --git a/README.md b/README.md
index 1809166..2b0c3c4 100644
--- a/README.md
+++ b/README.md
@@ -23,8 +23,8 @@ to manage backups on several storages mounted on multiple devices with a single
 - [x] update storage bind command
 - [ ] add storage remove command
 - [ ] add sync subcommand
-- [ ] add check subcommand
-  - [ ] check that all parents exist
+- [x] add check subcommand
+  - [x] check that all parents exist
 - [x] reorganize cmd option for storage
   - [x] use subcommand
 - [ ] backup subcommands
diff --git a/src/cmd_args.rs b/src/cmd_args.rs
index 0fe2eda..0db0217 100644
--- a/src/cmd_args.rs
+++ b/src/cmd_args.rs
@@ -53,7 +53,7 @@ pub(crate) enum Commands {
         remote_name: Option<String>,
     },
 
-    /// Check config files.
+    /// Check config files validity.
     Check {},
 
     /// Generate completion script.
diff --git a/src/cmd_check.rs b/src/cmd_check.rs
new file mode 100644
index 0000000..0ae7b96
--- /dev/null
+++ b/src/cmd_check.rs
@@ -0,0 +1,60 @@
+use std::path::PathBuf;
+
+use anyhow::{anyhow, Context, Result};
+
+use crate::{
+    backups::Backups,
+    devices,
+    storages::{Storage, StorageExt, Storages},
+};
+
+pub(crate) fn cmd_check(config_dir: &PathBuf) -> Result<()> {
+    info!("Config dir: {}", &config_dir.display());
+
+    let device = devices::get_device(&config_dir)?;
+    info!("Current device: {:?}", device);
+
+    let devices = devices::get_devices(&config_dir)?;
+    info!("Configured devices: {:?}", devices);
+
+    let storages = Storages::read(&config_dir)?;
+    info!("Storages: {:?}", storages);
+    if !(storages.list.iter().all(|(_name, storage)| match storage {
+        Storage::SubDirectory(storage) => storage.parent(&storages).is_some(),
+        _ => true,
+    })) {
+        return Err(anyhow!(
+            "Some SubDirectory doesn't have its parent in the storages list."
+        ));
+    };
+    info!("All SubDirectory's parent exists.");
+
+    for device in &devices {
+        let backups = Backups::read(&config_dir, &device)?;
+        for (name, backup) in &backups.list {
+            if name != backup.name() {
+                return Err(anyhow!(
+                    "The backup {} name and its key is different.",
+                    name
+                ));
+            }
+            let _device = backup
+                .device(&devices)
+                .context(format!("The backup {}'s device doesn't exist.", name))?;
+            if !(storages.list.contains_key(&backup.source().storage)) {
+                return Err(anyhow!(
+                    "The source of backup {} doesn't exist in storages.",
+                    &backup.name()
+                ));
+            }
+            if !(storages.list.contains_key(&backup.destination().storage)) {
+                return Err(anyhow!(
+                    "The destination of backup {} doesn't exist in storages.",
+                    &backup.name()
+                ));
+            }
+        }
+    }
+    println!("All check passed");
+    Ok(())
+}
diff --git a/src/main.rs b/src/main.rs
index d14a081..4c6ff47 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -28,10 +28,11 @@ use devices::{Device, DEVICESFILE, *};
 mod backups;
 mod cmd_args;
 mod cmd_backup;
+mod cmd_check;
+mod cmd_completion;
 mod cmd_init;
 mod cmd_storage;
 mod cmd_sync;
-mod cmd_completion;
 mod devices;
 mod inquire_filepath_completer;
 mod storages;
@@ -90,11 +91,7 @@ fn main() -> Result<()> {
             println!("{}", &config_dir.display());
         }
         Commands::Sync { remote_name } => cmd_sync::cmd_sync(&config_dir, remote_name)?,
-        Commands::Check {} => {
-            println!("Config dir: {}", &config_dir.display());
-            let _storages = Storages::read(&config_dir)?;
-            todo!()
-        }
+        Commands::Check {} => cmd_check::cmd_check(&config_dir)?,
         Commands::Backup(backup) => {
             trace!("backup subcommand with args: {:?}", backup);
             let repo = Repository::open(&config_dir).context(
@@ -123,9 +120,7 @@ fn main() -> Result<()> {
                 } => cmd_backup::cmd_backup_done(name, exit_status, log, repo, &config_dir)?,
             }
         }
-        Commands::Completion { shell } => {
-            cmd_completion::cmd_completion(shell)?
-        }
+        Commands::Completion { shell } => cmd_completion::cmd_completion(shell)?,
     }
     full_status(&Repository::open(&config_dir)?)?;
     Ok(())