Disclosed is a tidal current meter that measures the velocity of a tidal current. The tidal current meter includes an oscillator, a calculation section, a depression angle setup section, and a drive section. The oscillator is capable of transmitting an ultrasonic wave into water and receiving the reflection of the transmitted ultrasonic wave. The calculation section calculates the velocity in accordance with the Doppler shift frequency of the reflection received by the oscillator. The depression angle setup section sets a depression angle, that is, the angle formed by the transmission direction of the ultrasonic wave and a horizontal plane. The drive section drives the oscillator in such a manner as to transmit the ultrasonic wave and receive the reflection of the transmitted ultrasonic wave at the depression angle set by the depression angle setup section.