A liquid level detection device which protects at least a detection element, uses a less number of parts, can be easily assembled, and has reduced cost. A liquid level detection device (1) comprising: a float arm (2) which is provided with a float (2a) operating by following the displacement of a liquid level; a magnet (4) displaced as the float arm (2) operates; and a detection element (5) for detecting a change in the magnetism of the magnet (4). The liquid level detection device (1) also comprises; a first case body (8) consisting of a resin and covering the detection element (5); and a second case body (9) consisting of a resin and covering the first case body (8).
