To easily and rapidly absorb a dimensional error generated between a stopper part on the equipment side and a device body fitted to a door in a locking device favorable for a relatively large door.

In this locking device, a device body 6 is provided with a stay 10 slidably disposed in a case 20, a switching means 40 for switching a lock position of the stay 10 protruded from the case 20 by sliding the stay 10 and an unlock position of reducing the protruding quantity of the stay 10 by retreating the stay 10 into the case 20, a shaft connected to the switching means 40, and an operating knob 5 mounted to the protruding end of the shaft so as to operate the switching means 40. An engaging member 8 engaged with and disengaged from a stopper part 4, provided at the equipment side opposed inner surface, in the state of being fitted to the vertically intermediate part of a door 2 of the equipment is provided at the protruding end of the stay 10 through a connecting rod 7. Both ends of the rod 7 are connected to the protruding end of the stay 10 and the rear end part of the engaging member 8, in a length adjustable state to either one of them through screw parts 15, 72 and to the other through a removable engaging part.