PURPOSE: To charge a recording medium easily and, after charging, to keep the interval between a main magnetic pole and an auxiliary magnetic pole at a constant value by rotating any one of two magnetic poles, the main magnetic pole and the auxiliary magnetic pole, around a shaft.

CONSTITUTION: The recording medium 1 incorporated into a cassette 21 is charged together with the cassette 21 by inserting the cassette 21 into the direction shown by an arrow, the 1st guide is pushed by a pushing board 22 incorporated in the cassette 21 and rotated around the shaft 14. Consequently, the recording medium is put between the main magnetic pole 2 and the auxiliary magnetic pole 3 and the interval between both magnetic poles 2, 3 is set up to a fixed distance. The 1st guide 12 is fixed by a locking mechanism consisting of a locking board 18, a compression spring 20 and a plunger 19 and the titled device is ready for recording operation.