A speed measuring device has an antenna with directionality that transmits a transmission wave toward the moving body based on a transmission signal supplied from a Doppler sensor, and receives a reflected wave reflected by the moving body to generate and supply to the Doppler sensor a reception signal. An imaginary line extending along a direction in which a gain of the antenna is maximized is defined as an imaginary axis that indicates an orientation direction of the antenna. An antenna supporting unit is provided on a housing and supports the antenna so an inclination of the imaginary axis can be altered. A display is provided on an upper surface of the housing with a flat display surface of a rectangular shape facing upward and displays various display contents including the movement speed of the moving body on the display surface.