PURPOSE: To prevent theft of umbrella by constructing an umbrella accommodating part as capable of accommodating any type of umbrella, and arranging so that the locking motion takes place automatically.

CONSTITUTION: A lock device A is composed of a sliding member 60 having opening/shutting members 50, 50' confronting a driving member 20 and unlocking member 30 installed at the rear of a cylinder lock, a detaining member 70, and the first and the second resilient member 80, 90 which energize the two members 60, 70. The unlocking member 30 is positioned as perpendicularly intersecting the sliding member 60, and a projection 63 on this member 60 is arranged as contacting when it 60 moves in the direction of advancing, and a rack 61 provided on the unlocking member 30 is made possible to be engaged by the detaining member 70 for the sliding member 60 so that the opening/ shutting members 50, 40' are put in the shut state. When the unlocking member 30 is moved with the unlocking operation, the detaining member 70 is separated so that the shut state is disengaged.