To record data capable of displaying or printing an accurate signal waveform surely in a short time.

A waveform recording apparatus includes: a signal processing part for performing signal-processing on an input signal; an A/D conversion part for A/D converting the processed signal; and a control part for executing waveform recording processing 10 for performing signal-processing on the input signal in accordance with a specified processing condition and sequentially recording sampling values of the digital signal A/D converted by the A/D conversion part in a data recording part in time series. When a new processing condition is specified during the execution of the recording processing 10 (step 14), the control part performs signal-processing on the input signal in accordance with the new processing condition, records first information (a control flag with a value "1") capable of specifying that the specification of the new processing condition correspondingly to an initial sampling value subjected to signal processing in accordance with the new processing condition (step 16) and records second information (setting information) capable of specifying the contents of the new processing condition correspondingly to the first information (step 17).