A living body stimulation device comprising: an outputting unit that is configured to output a stimulation signal to a living body, wherein: the stimulation signal is a signal in which a positive pulse group and a negative pulse group appear alternately at predetermined intervals, the positive pulse group being constituted by a plurality of pulses whose potential rises toward the plus-side, the negative pulse group being constituted by a plurality of pulses whose potential falls toward the minus-side; when a single period of the stimulation signal is divided into four terms consisting of a first term, a second term, a third term, and a fourth term, the positive pulse group appears in the first term and the second term, wherein, in the first term, the pulse width gradually widens, and in the second term, the pulse width gradually narrows in a manner that change-over-time thereof is reverse of the change-over-time of the pulse width in the first term, and the negative pulse group appears in the third term and the fourth term, wherein, in the third term, the pulse width gradually widens, and in the fourth term, the pulse width gradually narrows in a manner that change-over-time thereof is reverse of the change-over-time of the pulse width in the third term; characterized in that the stimulation signal includes: a discharge pulse that is provided immediately before the positive pulse group and whose potential rises toward the plus-side, and a discharge pulse that is provided immediately before the negative pulse group and whose potential falls toward the minus-side. the stimulation signal is a signal in which a positive pulse group and a negative pulse group appear alternately at predetermined intervals, the positive pulse group being constituted by a plurality of pulses whose potential rises toward the plus-side, the negative pulse group being constituted by a plurality of pulses whose potential falls toward the minus-side; when a single period of the stimulation signal is divided into four terms consisting of a first term, a second term, a third term, and a fourth term, the positive pulse group appears in the first term and the second term, wherein, in the first term, the pulse width gradually widens, and in the second term, the pulse width gradually narrows in a manner that change-over-time thereof is reverse of the change-over-time of the pulse width in the first term, and the negative pulse group appears in the third term and the fourth term, wherein, in the third term, the pulse width gradually widens, and in the fourth term, the pulse width gradually narrows in a manner that change-over-time thereof is reverse of the change-over-time of the pulse width in the third term; the positive pulse group appears in the first term and the second term, wherein, in the first term, the pulse width gradually widens, and in the second term, the pulse width gradually narrows in a manner that change-over-time thereof is reverse of the change-over-time of the pulse width in the first term, and the negative pulse group appears in the third term and the fourth term, wherein, in the third term, the pulse width gradually widens, and in the fourth term, the pulse width gradually narrows in a manner that change-over-time thereof is reverse of the change-over-time of the pulse width in the third term; characterized in that the stimulation signal includes: a discharge pulse that is provided immediately before the positive pulse group and whose potential rises toward the plus-side, and a discharge pulse that is provided immediately before the negative pulse group and whose potential falls toward the minus-side. a discharge pulse that is provided immediately before the positive pulse group and whose potential rises toward the plus-side, and a discharge pulse that is provided immediately before the negative pulse group and whose potential falls toward the minus-side.