A peak suppressing device (10) includes: a subtracting unit (11) that subtracts a predetermined threshold from an amplitude value of an input signal and generates a first peak signal; a multiplying unit (12) that multiplies the first peak signal by a weight coefficient and generates a second peak signal; a band limiting filter (13) that limits a band of the second peak signal, and generates a third peak signal; a subtracting unit (14) that subtracts the third peak signal from the input signal; and a weight coefficient generating unit (15) that generates the weight coefficient based on a value, the value being an amplitude value of the first peak signal divided by an amplitude value of a fourth peak signal generated when a convolution arithmetic operation is performed on by using at least a tap coefficient used in a center tap of the band limiting filter (13).