PURPOSE: To surely erase a starting part by providing a means to detect the starting part of a magnetic tape, rewinding a fixed quantity of the tape after the starting part is detected and starting an erasing operation at that point.

CONSTITUTION: A starting part detector 15 consists of a light emitting element 2, a light receiving element 3, resistances R1WR3 and a transistor 7 and the optical signal of the light emitting element 2 is given to the light receiving element 3 through a video tape 17. When a leader tape is detected, a line l1 becomes high-level, a control circuit 8 stops tape traveling, next it is rewound at low speed by a motor 16 and the reel pulse of a reel pulse generator 5 is counted to a set value and stopped. Next, the tape is wound again, an erasing current is impressed on an erasing head 6 through an erasing bias oscillation circuit 9, therefore, the erasing omission in the starting part is eliminated and it can be surely erased.