To securely provide a clearance between sheet tips and an inner wall of a cassette regulating the sheet tips when fitting the sheet cassette to a device main body, without being affected by the magnitude of the force by a user fitting the cassette to the device main body and paper types.

The sheet cassette 2 is detachably fitted to the device main body 1 in the carrying direction of sheets S. The sheet cassette 2 includes a sheet stacking member 21 rotatably provided to make the stacked sheets S abut on a pickup roller 3 arranged in the device main body 1 side after fitting to the device main body 1 and a tip regulating member 25 situated in a regulating position for regulating the tips of the sheets S before fitting to the device main body 1 and moved to a regulation release position separated from the tips of the sheets S by the fitting operation to the device main body 1.