An object of the present invention is to provide a heart rate monitor built-in insert earphone. A front outer shells 10, circuit board assembly 20, Kosoto 30, has a light guide tube 40, front outer shells are stretched to the front, forming a sound conducting tube, sound-guiding tube recessed rearward, to form a light permeabilizing tank 12, the circuit board assembly includes a fixed member 21, the circuit board 22, the speaker 23 has an optical sensor 24, the fixing member central portion, the sound guide hole 211 opened, and the circuit board, the fixing portion 221, connecting portion 222 includes a mounting portion 223, fixing unit covers the fixing member, the speaker is mounted to the mounting portion, the optical sensor, the light front outer shells vitrification corresponds to the vessel, fixed to the fixed outer surface, Kosoto is to cap the front outer end, the light guide tube has a circular tube bottom 41, the tube bottom of the light pipe, a circuit board corresponding to the sound conducting hole of the fixing member of the assembly, set up a sound conducting port 42, the bottom of the tube of the light guide tube, corresponds to the light vitrification tank of the front outer shells, projecting to the rear, the light vitrification piece 43 formed, the light guide tube is attached to the sound guide tube outside of the front outer shells, light vitrification piece of the light guide tube is engaged in correspondence with the front outer shells of light vitrification tank. It can be measured more accurate heartbeat signal.FIELD 2【課題】心拍計内蔵インサートイヤホンを提供する。【解決手段】前外殼10、回路基板アセンブリ20、後外殼30、導光管40を有し、前外殼は、前方へと延伸し、導音管を形成し、導音管は後方へと陥没し、光透化槽12を形成し、回路基板アセンブリは、固定部材21、回路基板22、スピーカー23、光学センサー24を有し、固定部材中央部には、導音孔211を開設し、回路基板は、固定部221、連接部222、取り付け部223を有し、固定部は、固定部材を覆い、スピーカーは、取り付け部に取り付けられ、光学センサーは、前外殼の光透化槽に対応し、固定部外表面に固定され、後外殼は、前外殼後端に蓋をし、導光管は、円形の管底41を有し、導光管の管底は、回路基板アセンブリの固定部材の導音孔に対応し、導音口42を開設し、導光管の管底は、前外殼の光透化槽に対応し、後方へと突出し、光透化片43を形成し、導光管は、前外殼の導音管外に取り付けられ、導光管の光透化片は、前外殼の光透化槽内に対応して係合さ
