PURPOSE: To miniaturize a device without losing the reliability by supporting a guide pin with an elastic means and also pressing the guide pin in the direction opposite to the advancing direction when the guide pin is entered into a 2nd groove of guide grooves.

CONSTITUTION: A guide holding member 11, an elastic member 10 consisting of a twist spring 12, and a stopper 13 are provided in a transporting mechanism of the loading device. The holding member 11 consists of, e.g. a planar spring, and the one end is fitted to a guide plate 3 by a locking pin 11 a and the another end is arranged along the horizontal part 3b beyond a terminal wall 3d of the horizontal part 3b, at the lower side of the horizontal part 3b of the guide groove 3a. In the loading device, the guide pin 1a which is engaged with an inclined slot provided on a moving plate by the movement of the moving side plate to the direction X, is moved along the horizontal part 3b of the guide groove 3a. The pin 1a is pressed in the direction of the vertical part 3c by the inclined surface of the slot 2a and advanced into the vertical part 3c while pressing the member 11 and the spring downward.