Provided is a body-attachable biometric signal acquisition device. The body-attachable biometric signal acquisition device includes: a main body including a sensor acquiring a biometric signal in a state of closely adhering to a surface of a body； and a first fixing portion winding the body to fix the main body to the body, wherein the first fixing portion includes a first strap winding the body, the first strap includes a framework formed of an elastic material, and when the first strap winds the body to fasten the main body and the first fixing portion to the body, a pressure applied by the sensor to the surface of the body is generated by an elastic restoring moment generated by the framework, and a gap is present between a portion of an outer surface of the first strap, and the surface of the body, the portion being positioned between the framework and the surface of the body. An air cushion is provided to prevent wobbling of the main body caused by an excessive space formed due to body size variation.
