Lubricating oil supply control device for construction machine

A control device is produced for enabling a locked-up state at a low speed range and preventing thereby-caused insufficiency in the lubricating oil supply amount to a transmission. The control device controls the lubricating oil supply amount to a transmission in a construction machine including a torque converter with a lock-up clutch. The control device includes a clutch state determining section, a lubricating oil amount detecting section and a lock-up clutch controlling section. The clutch state determining section determines whether or not the lock-up clutch (7) is being coupled. The lubricating oil amount detecting section detects whether or not the lubricating oil supply amount to the transmission (2) is short of a preliminarily set supply amount. The lock-up clutch controlling section decouples the lock-up clutch (7) when the lock-up clutch (7) is being coupled and the lubricating oil supply amount is short of the preliminarily set supply amount.