A biosensor is provided. The biosensor includes a first housing, a second housing and a hinge. The first housing includes a first finger pad with a fixation structure, and a first circuit board fixed on the first finger pad. The second housing includes a second finger pad with a fixation structure, and a second circuit board fixed on the second finger pad. The finger pads are provided with transparent optical windows at a corresponding position to let a light detector of the second circuit board receive a signal from a light emitter of the first circuit board, thereby achieving the purpose of stably assembling the light emitter or the light detector.本創作相關於一種生物感測器。生物感測器包括第一殼體、第二殼體與轉樞。第一殼體包括具有固定結構的第一指墊，及固定在第一指墊上的第一電路板，第二殼體包括具有固定結構的第二指墊，及固定在第二指墊上的第二電路板。第一指墊與第二指墊分別具有對應的透明光窗，藉以使第二電路板上的光感測器，得以接收第一電路板上的發光器件的訊號。經由上述固定結構達到穩定組裝發光器件或感測器件的效果。
