In an error correction device, a frame generation section receives pulse signals as temperature information of a power switching element transmitted from a PWM comparator. The frame generation section sets a first correction pulse signal, a second correction pulse signal and the temperature information sequentially into each frame. A pulse width of the first correction pulse signal corresponds to a pulse width when a time ratio thereof becomes 100%. A pulse width of the second correction pulse signal corresponds to a pulse width when a time ratio thereof becomes 50%. A microcomputer receives the temperature information through a photocoupler and corrects the received temperature information. The microcomputer calculates a temperature detection value of the power switching element on the basis of the corrected temperature information.