A waveform shaping filter according to an embodiment includes at least one filter stage and a control circuit. The filter stage includes a differentiation signal generation circuit, a proportional signal generation circuit, and an adder circuit. The differentiation signal generation circuit generates a differentiation signal obtained by amplifying a differentiation component of an input signal. The proportional signal generation circuit generates a proportional signal obtained by amplifying the input signal. The adder circuit outputs an output signal obtained by adding the proportional signal and the differentiation signal. The control circuit compares the output signal and a first detection level, detects at least one of an overshoot and an undershoot of the output signal, and controls a time constant of the filter stage, based on a detection result.