A filter inspection apparatus for inspecting quality related to a placement state of a predetermined object to be disposed which is to be disposed inside a filter for a smoking article, the filter inspection apparatus comprising: an irradiation unit that irradiates a target filter with an inspection electromagnetic wave having a predetermined frequency, the target filter being the filter for a smoking article as an object to be inspected; a receiving unit that receives a reflected electromagnetic wave from the target filter, resulting from the inspection electromagnetic wave emitted by the irradiation unit; an antenna unit that is disposed so as to face the target filter, and propagates the inspection electromagnetic wave and the reflected electromagnetic wave; an acquisition unit that acquires, on the basis of a reflected signal obtained by the receiving unit, predetermined information related to intensity of the reflected signal or phase shift of the reflected signal associated with the placement state of the predetermined object to be disposed inside the target filter; a determination unit that determines the quality of the placement state of the predetermined object to be disposed which is disposed in the target filter, on the basis of the predetermined information acquired by the acquisition unit; and reflection unit that is disposed on a rear part of the target filter, the rear part being located on a side opposite to the antenna unit, and is formed so as to reflect a transmission electromagnetic wave on a side of the target filter again, the transmission electromagnetic wave being a part of the emitted inspection electromagnetic wave and being transmitted through the target filter, wherein the receiving unit receives a secondary reflected electromagnetic wave which is an electromagnetic wave obtained by reflecting the transmission electromagnetic wave by the reflection unit, in addition to the reflected electromagnetic wave from the target filter. an irradiation unit that irradiates a target filter with an inspection electromagnetic wave having a predetermined frequency, the target filter being the filter for a smoking article as an object to be inspected; a receiving unit that receives a reflected electromagnetic wave from the target filter, resulting from the inspection electromagnetic wave emitted by the irradiation unit; an antenna unit that is disposed so as to face the target filter, and propagates the inspection electromagnetic wave and the reflected electromagnetic wave; an acquisition unit that acquires, on the basis of a reflected signal obtained by the receiving unit, predetermined information related to intensity of the reflected signal or phase shift of the reflected signal associated with the placement state of the predetermined object to be disposed inside the target filter; a determination unit that determines the quality of the placement state of the predetermined object to be disposed which is disposed in the target filter, on the basis of the predetermined information acquired by the acquisition unit; and reflection unit that is disposed on a rear part of the target filter, the rear part being located on a side opposite to the antenna unit, and is formed so as to reflect a transmission electromagnetic wave on a side of the target filter again, the transmission electromagnetic wave being a part of the emitted inspection electromagnetic wave and being transmitted through the target filter, wherein the receiving unit receives a secondary reflected electromagnetic wave which is an electromagnetic wave obtained by reflecting the transmission electromagnetic wave by the reflection unit, in addition to the reflected electromagnetic wave from the target filter.