Sensors that detect the distance and the position of an object are used in a lot of fields. Among of them, the sensors that measure the shift value of an object are a large scale system, furthermore, an accurate mounting of these sensors is required. To solve these problems, this paper proposes an optical linear sensor using one-side frosted glass. This sensor can detect the position of the light irradiation point only by putting it directly on the target. For a parallel light, it is irrelevant to the distance between this sensor and the source of light because the size of light beam is unchanged according to the distance. This sensor assumes that the sensor’s surface irradiated roughly vertical with the light, and does not need a high accurate mounting. Therefore, it can be easily used.