The objective of the present invention is to provide a muscular electric stimulation device with which it is possible for a muscle to be stimulated efficiently, which has satisfactory feeling in use even when used for an extended period of time, and with which a user can be encouraged to use the device proactively. This muscle electric stimulation device (1) is configured in such a way as to impart electrical stimulation to a muscle. The electrical stimulation comprises alternately repeating a first output period (2-1, 3-1, 4-1) in which a fifth burst wave (20 Hz), serving as a first electrical signal causing the muscle to experience incomplete tetanus and/or complete tetanus, is output, and a second output period (2-2, 3-2, 4-2) in which a second burst wave (4 Hz), serving as a second electrical signal causing the muscle to twitch, is output.一種肌肉電氣刺激裝置，其中，提供：可有效率地刺激肌肉之同時，即使長時間使用，使用感亦佳，可促進對於使用者積極性繼續使用之肌肉電氣刺激裝置者。肌肉電氣刺激裝置(1)係呈賦予電氣刺激於肌肉地加以構成。該電氣刺激係交互地加以反覆加以輸出作為使肌肉引起不完全強縮及完全強縮之至少一方之第1電氣信號之第5破裂波(20Hz)之第1輸出期間(2-1，3-1，4-1)，和加以輸出作為使肌肉引起單收縮之第2電氣信號之第2破裂波(4Hz)之第2輸出期間(2-2，3-2，4-2)而成。
