A skin measuring device for spectroscopic measurement of the skin of a body part is provided. The skin measuring device has a press-on frame with a window and a flat face. The skin measuring device has an ATR infrared spectrometer which includes an ATR crystal that is secured to the press-on frame and that has a sample stage which is arranged in the window and faces in the same direction as the flat face of the press-on frame. An encircling means surrounds the body part and thereby supports the skin measuring device on the body part. The surface of the flat face of the press-on frame is pressed against the skin of the body pan by the encircling means in a comfortably wearable manner when the skin measuring device is worn such that the sample stage is in contact with the skin for spectroscopic measurement by the ATR spectrometer.