A stethoscope is provided with two head portions for fitting two diaphragms different in caliber on a head main portion, having diverse design properties and functions.A stethoscope head comprising a head main portion and a conduit connecting portion provided on the head main portion, wherein said head main portion comprises a main head portion and a sub-head portion formed from a transparent or semitransparent element formed in the opposite direction each other with the pipe connecting port put therebetween; the main head portion comprises a transparent or semitransparent main diaphragm connected to the conduit connecting port, and the sub-head portion is provided with spaces for receiving the sub-diaphragm for high frequency and or narrow area stethoscope or various functions, and is provided with mounting means for mounting the sub-diaphragm or the apparatus on the sub-head portion.