A fire detector base, comprising: a pedestal configured to attach thereto a detector body, the pedestal including a bottom wall, and the detector body including an electric circuit for detecting fire; external connection terminals configured to be electrically connected to an external wiring, the external connection terminals being fixed to the bottom wall; internal terminals to which the electric circuit is electrically connected, the internal terminals being fixed to the bottom wall; external connection terminal blocks; and internal terminal blocks, the bottom wall includes a first bottom portion and a second bottom portion facing the first bottom portion, each external connection terminal block is protruded upward from the second bottom portion and houses one external connection terminal, each internal terminal block is fixed to the second bottom portion and houses one internal terminal, the second bottom portion holding the external connection terminals and the internal terminals, the first bottom portion covering the external connection terminals, the respective internal terminals corresponding to the external connection terminals in one-to-one, each of the internal terminals being electrically connected to a target external connection terminal that is one corresponding to each internal terminal noted, of the external connection terminals, in each of the internal terminals, a distance (L1, L2, or L3) from each internal terminal to the target external connection terminal being shorter than a distance (L61, L62; L61, L63; or L62, L63) from each internal terminal to any other one of the internal terminals, and shorter than a distance (L51, L52; L51, L53; or L52, L53) from the target external connection terminal to any other one of the external connection terminals. a pedestal configured to attach thereto a detector body, the pedestal including a bottom wall, and the detector body including an electric circuit for detecting fire; external connection terminals configured to be electrically connected to an external wiring, the external connection terminals being fixed to the bottom wall; internal terminals to which the electric circuit is electrically connected, the internal terminals being fixed to the bottom wall; external connection terminal blocks; and internal terminal blocks, the bottom wall includes a first bottom portion and a second bottom portion facing the first bottom portion, each external connection terminal block is protruded upward from the second bottom portion and houses one external connection terminal, each internal terminal block is fixed to the second bottom portion and houses one internal terminal, the second bottom portion holding the external connection terminals and the internal terminals, the first bottom portion covering the external connection terminals, the respective internal terminals corresponding to the external connection terminals in one-to-one, each of the internal terminals being electrically connected to a target external connection terminal that is one corresponding to each internal terminal noted, of the external connection terminals, in each of the internal terminals, a distance (L1, L2, or L3) from each internal terminal to the target external connection terminal being shorter than a distance (L61, L62; L61, L63; or L62, L63) from each internal terminal to any other one of the internal terminals, and shorter than a distance (L51, L52; L51, L53; or L52, L53) from the target external connection terminal to any other one of the external connection terminals.