A coolant supply apparatus includes variable delivery coolant pump (100) pumping up coolant from coolant tank (104), a plurality of branch passages (120 to 124) allowing coolant (108) delivered from coolant pump (100) to flow separately to a plurality of parts of a machine tool, and machine control unit (110) turning on and off on-off valves (136) of the plurality of branch passages (120 to 124), wherein machine control unit (110), in response to a jet coolant instruction, opens only one branch passage to intensively supply coolant (108) to the branch passage at the maximum delivery rate of coolant pump (100) and closes the other branch passages.