This microchannel heat exchanger includes: a heat exchanger body including a channel layer stack formed in such a manner that a plurality of high-temperature channel layers provided with a channel for a high-temperature fluid and a plurality of low-temperature channels layers provided with a channel for a low-temperature fluid are alternately stacked, an inlet and an outlet for the high-temperature fluid, and an inlet and an outlet for the low-temperature fluid; and a control board that is fixed in a stacking direction of the heat exchanger body, and that at least installs a plurality of temperature sensors that are inserted in the stacking method of the heat exchanger body in such a manner that a sensing point is arranged near each of the inlet and the outlet for the high-temperature fluid and the inlet and the outlet for the low-temperature fluid.