PURPOSE: To shorten machining time by automatically grabbing a pallet by means of a conveying robot, fixing it on a fixing base of a machining grinder, roughly grinding an object to be machined, automatically conveying the object to be machined to the following process, and finishing the object to be machined by means of a profile grinder.

CONSTITUTION: A pallet 2 is automatically grabbed and conveyed by means of a gripper 401 of a conveying robot so as to be inserted and fixed in an automatic quick clamp chuck 103 of a fixing base 102 in a machining grinder 1. An object 3 to be machined is roughly ground by means of the machining grinder 1. After a finish of rough grinding, the gripper 401 of the conveying robot automatically grabs the pallet 2 again and conveys it to the following process, and the pallet 2 is fixed in the fixing base of a profile grinder, and subsequently, the object 3 to be machined is finished. In this way, a machining time can be shortened, while the calorific value of the object 3 to be machined can be suppressed.