Slip lock-up control device for vehicle

A slip lock-up control device for a vehicle, comprising:

• a torque converter placed between an engine and a transmission, the torque converter having a lock-up clutch;
• and
• slip lock-up control means for, when a lock-up engagement condition is fulfilled when the lock-up clutch is in a released state, using engine torque information which is input torque, performing slip lock-up control using a lock-up pressure difference command for matching an actual slip rotational speed to a target slip rotational speed, wherein
• during the slip lock-up control, when in an engine torque unstable range for which an engine torque has a rise gradient with respect to a rise change of an engine speed, the slip lock-up control means further has a function for setting the lock-up pressure difference command to a second lock-up pressure difference command for which a pressure difference fluctuation is averaged more than a first lock-up pressure difference command used in a range other than the engine torque unstable range.