The present invention provides an object-sensing device capable of estimating the presence of an object attached on a sensing surface, the kind of the object and the state of the object. An image is formed by a lens with light via the sensing surface, and the light is received by a light-receiving element portion in which a plurality of micro-light-receiving elements are arranged. In the object detection mode, totally reflected light from the sensing surface is received by the light-receiving element portion. The components are arranged at an angle that allows total reflection when there is no object, and does not allow the total reflection condition to be satisfied when there is an object. In the light scattering object detection mode, scattered light from the sensing surface is received by the light-receiving element portion. A signal pattern is obtained by joining detection signal levels of the micro-light-receiving elements in accordance with the arrangement of the micro-light-receiving elements. An increase portion or a drop portion of the signal pattern that appears in accordance with the presence of the object or a difference in the state thereof is analyzed, so that the kind and the state of the object such as a rain drop, muddy water, fogging, ice or the like are estimated.