A biological information measurement device includes a device main body and a band configured to secure the device to a body part of a user. The device main body contacts the users skin to thereby acquire biological information about the user, and presents a non-rectangular parallelogram surface in plan view. The parallelogram surface has two longitudinal edges disposed along a longitudinal direction, and two oblique edges disposed along an oblique direction that is transverse to, but not perpendicular to, the longitudinal direction. The band is attached to the oblique edges of the device main body, and generally extends in the longitudinal direction.
