A machine configured to detect deterioration of lubricant, comprising: a machine body; a lubricant deterioration sensor (137, 139) which is configured to detect deterioration of the lubricant, which lubricant is for reducing friction generated at a movable portion of the machine body; and a cleaning member which is configured to clean the lubricant deterioration sensor (137, 139), wherein the machine body includes a sensor side portion at which the lubricant deterioration sensor (137, 139) is mounted and a cleaning member side portion which is movable with respect to the sensor side portion and at which the cleaning member is mounted, the lubricant deterioration sensor includes a light emitting element which is configured to emit light, a color light reception element which is configured to detect color of received light, and a gap forming member having gap forming surfaces (61c, 62a) at which an oil gap into which the lubricant enters is formed, the gap forming member is configured to transmit the light emitted from the light emitting element, the oil gap is disposed on an optical path from the light emitting element to the color light reception element, and the cleaning member is disposed at a position where the cleaning member contacts with the gap forming surfaces (61c, 62a) when the sensor side portion and the cleaning member side portion move relatively wherein the machine is configured such that when the cleaning member side portion is rotated relative to the sensor side portion at which the lubricant deterioration sensor (137, 139) is mounted, the cleaning member is inserted into the oil gap of the gap forming member and moves in the rotation direction of the cleaning member side portion through the oil gap so as to contact with the gap forming surfaces (61c, 62a). a machine body; a lubricant deterioration sensor (137, 139) which is configured to detect deterioration of the lubricant, which lubricant is for reducing friction generated at a movable portion of the machine body; and a cleaning member which is configured to clean the lubricant deterioration sensor (137, 139), wherein the machine body includes a sensor side portion at which the lubricant deterioration sensor (137, 139) is mounted and a cleaning member side portion which is movable with respect to the sensor side portion and at which the cleaning member is mounted, the lubricant deterioration sensor includes a light emitting element which is configured to emit light, a color light reception element which is configured to detect color of received light, and a gap forming member having gap forming surfaces (61c, 62a) at which an oil gap into which the lubricant enters is formed, the gap forming member is configured to transmit the light emitted from the light emitting element, the oil gap is disposed on an optical path from the light emitting element to the color light reception element, and the cleaning member is disposed at a position where the cleaning member contacts with the gap forming surfaces (61c, 62a) when the sensor side portion and the cleaning member side portion move relatively wherein the machine is configured such that when the cleaning member side portion is rotated relative to the sensor side portion at which the lubricant deterioration sensor (137, 139) is mounted, the cleaning member is inserted into the oil gap of the gap forming member and moves in the rotation direction of the cleaning member side portion through the oil gap so as to contact with the gap forming surfaces (61c, 62a).