A current sensor, comprising: a core, the core being made from magnetic member, the core including a plurality of groove portions and at least one separation wall portion separating the groove portions from one another; a housing, the housing being made from a non-magnetic material, the housing covering the core along a contour of the core, the housing including a plurality of recessed grooves formed at the housing along the groove portions, respectively; a plurality of conductors, the conductors positioned in the groove portions, respectively, the conductors allowing a current being measured to flow therein; a circuit board, the circuit board fixed to the housing, the circuit board including a through hole and a land formed at a surrounding of the through hole, the through hole penetrating through the circuit board in a direction corresponding to an inserting direction of the conductor; a plurality of detection elements, the detection elements detecting a magnitude of a magnetic field generated in accordance with the current being measured flowing in the conductors, at least one detection element positioned in each of the recessed grooves, the detection elements positioned closer to an opening end side of the groove portion relative to the conductor positioned in the groove portion, the detection elements being arranged so that a detecting direction of the detection elements is directed along a distance direction of the groove portions, wherein the distance direction is defined as the spacing direction between the plurality of conductors, each of the detection elements including a connection terminal, the connection terminal inserted and positioned in the through hole, the connection terminal electrically connected to the land; and a guide portion, the guide portion provided at the housing, the guide portion guiding the connection terminal to the through hole. a core, the core being made from magnetic member, the core including a plurality of groove portions and at least one separation wall portion separating the groove portions from one another; a housing, the housing being made from a non-magnetic material, the housing covering the core along a contour of the core, the housing including a plurality of recessed grooves formed at the housing along the groove portions, respectively; a plurality of conductors, the conductors positioned in the groove portions, respectively, the conductors allowing a current being measured to flow therein; a circuit board, the circuit board fixed to the housing, the circuit board including a through hole and a land formed at a surrounding of the through hole, the through hole penetrating through the circuit board in a direction corresponding to an inserting direction of the conductor; a plurality of detection elements, the detection elements detecting a magnitude of a magnetic field generated in accordance with the current being measured flowing in the conductors, at least one detection element positioned in each of the recessed grooves, the detection elements positioned closer to an opening end side of the groove portion relative to the conductor positioned in the groove portion, the detection elements being arranged so that a detecting direction of the detection elements is directed along a distance direction of the groove portions, wherein the distance direction is defined as the spacing direction between the plurality of conductors, each of the detection elements including a connection terminal, the connection terminal inserted and positioned in the through hole, the connection terminal electrically connected to the land; and a guide portion, the guide portion provided at the housing, the guide portion guiding the connection terminal to the through hole.