PROBLEM TO BE SOLVED: To provide an antenna device in which each of a plurality of receiving antennae can be attached to a proper position, regardless of the body type of a reagent.SOLUTION: There is provided an antenna device 4 which receives a wireless signal wirelessly transmitted from a capsule type endoscope device 3 that is introduced into a reagent 2 to acquire information in the body of the reagent 2. The antenna device 4 comprises: at least two receiving antennae 41(n) for receiving the wireless signal and a sheet part 42 in which each of the at least two receiving antennae 41(n) is arranged and which has expanding and contracting parts 45 capable of changing the relative positional relationship between the at least two receiving antennae 41(n) and the reagent 2.SELECTED DRAWING: Figure 2
