A proximity sensor, comprising: two or more coils (11, 12, 13) disposed in a predetermined positional relationship; a distance calculation unit (31, 32) which is configured to calculate respective pieces of distance information from the coils (11, 12, 13) which obtain a reception result to a detection object on the basis of the reception results of a plurality of coils (11, 12, 13) from among the coils (11, 12, 13); and a position estimating unit which is configured to estimate a distance and a bearing of the detection object on the basis of each piece of distance information and the positional relationship, the proximity sensor being characterized in that each of the coils (11, 12, 13) is coaxially disposed, that each of the coils (11, 12, 13) is disposed on the same plane, and that the coils (11, 12, 13) have different winding diameters, wherein: the two or more coils (11, 12, 13) are configured to be combined, wherein each of the combined coils is configured to be selectively excited; the distance calculation unit (31, 32) is configured to calculate respective pieces of distance information from the plurality of coils (11, 12, 13) to the detection object for each selective excitation of each of the coils (11, 12, 13); and the position estimating unit is configured to estimate the distance and the bearing of the detection object on the basis of the positional relationship and each piece of distance information calculated for each of the selective excitation, only one of the coils being excited in a first selective excitation, and two of the coils being excited in a second selective excitation. two or more coils (11, 12, 13) disposed in a predetermined positional relationship; a distance calculation unit (31, 32) which is configured to calculate respective pieces of distance information from the coils (11, 12, 13) which obtain a reception result to a detection object on the basis of the reception results of a plurality of coils (11, 12, 13) from among the coils (11, 12, 13); and a position estimating unit which is configured to estimate a distance and a bearing of the detection object on the basis of each piece of distance information and the positional relationship, the proximity sensor being characterized in that each of the coils (11, 12, 13) is coaxially disposed, that each of the coils (11, 12, 13) is disposed on the same plane, and that the coils (11, 12, 13) have different winding diameters, wherein: the two or more coils (11, 12, 13) are configured to be combined, wherein each of the combined coils is configured to be selectively excited; the distance calculation unit (31, 32) is configured to calculate respective pieces of distance information from the plurality of coils (11, 12, 13) to the detection object for each selective excitation of each of the coils (11, 12, 13); and the position estimating unit is configured to estimate the distance and the bearing of the detection object on the basis of the positional relationship and each piece of distance information calculated for each of the selective excitation, only one of the coils being excited in a first selective excitation, and two of the coils being excited in a second selective excitation. the two or more coils (11, 12, 13) are configured to be combined, wherein each of the combined coils is configured to be selectively excited; the distance calculation unit (31, 32) is configured to calculate respective pieces of distance information from the plurality of coils (11, 12, 13) to the detection object for each selective excitation of each of the coils (11, 12, 13); and the position estimating unit is configured to estimate the distance and the bearing of the detection object on the basis of the positional relationship and each piece of distance information calculated for each of the selective excitation, only one of the coils being excited in a first selective excitation, and two of the coils being excited in a second selective excitation.