A joystick device is provided including a larger number of proportional control actuators than the prior art thereby enjoying higher operability. Joystick device includes an operation lever having a grip portion provided on a surface thereof with a slide switch substantially T-shaped in section. The slide switch has a web portion connected to an upper surface of a shaft rotatably supported at a lower portion of the operation panel. A magnet is embedded in a lower surface of the shaft. When the operator slides the slide switch, the web portion of the slide switch pivots about the shaft, while the shaft rotates to displace the magnet in accordance with pivotal movement of the web portion. A magnetic sensor detects a variation in magnetic field intensity in accordance with displacement of the magnet, whereby a voltage proportional to the amount of movement of the slide switch is outputted.