A temperature correcting apparatus divides an actually measured waveform of correcting voltages, which are required at each of different temperatures, by a minimum resolution of D/A conversion; obtains voltage digital values representing voltage values at individual dividing points of the actually measured waveform, and obtains times corresponding to the voltage digital values; prestores pairs of the voltage digital values and times together with addresses as correcting data; reads out the correcting data in response to the detection address representing the temperature; extracts or calculates from the correcting data the voltage digital values and times about the correcting voltages required by the detection address; and sequentially supplying a D/A converter (36) with the resultant voltage digital values in synchronization with the corresponding times.