A biological signal measuring equipment used in a measurement of a biological signal in a head portion, has a jaw contact portion that comes into contact with a forehead; an occiput contact portion that comes into contact with an occiput; and a supporter that is interposed in a front and rear direction of the head portion and is supported by the head portion by using the jaw contact portion and the occiput contact portion as ends. The biological signal measuring equipment performs the measurement in the same manner as the case of measuring a wave motion of a short period, even in the case of measuring the wave motion of a long period generated in a head portion.