PURPOSE: To accurately measure the strength of the green of a golf course by providing a measuring device main body having a sensor arranged on the rear surface thereof to a measuring device support in a freely tiltable manner.

CONSTITUTION: A measuring device main body 12 is formed into a box shape and provided to a measuring device support 11 in a freely tiltable manner. A sensor 13 is arranged on the rear surface of the main body 12 and constituted, for example, using a piezoelectric film. A proximity switch 17 is a magnetic sensor to detect the approach of a magnet 19. This measuring device is set to lawn grass and the main body 12 is tilted from adefinite height like a pendulum. Whereupon, the sensor 13 is operated by the first tilting of the main body 12 to come into contact with the lawn grass and the strength of the lawn grass is measured on the basis of the contact pressure with the lawn grass. When the main body 12 is returned, a buzzer sound of completion is emitted from a buzzer and the LED of a display device 14 displays the strength of lawn grass in four figures on the basis of the signal from the sensor 13. When the strength of lawn grass is desired to be again measured, a reset button 15 is pushed to set the LED of the display device to zero. When the voltage of a battery is lowered, the buzzer 18 emits a continuous sound.