A measurement sensor package (1, 1A), comprising: a substrate including a substrate body including a plurality of dielectric layers stacked on one another, the substrate body being a rectangular plate and including a first recess and a second recess on a first surface thereof, the first recess being configured to contain a light emitter, the second recess being configured to contain a light receiver, and one or more ground via conductors located outward from the first recess and the second recess included in the substrate body in a plan view, the one or more ground via conductors being connectable to a ground potential; a lid being a plate covering the first recess and the second recess, the lid comprising an insulating material, the lid being configured to be put in contact with a body part and being configured to transmit light emitted from the light emitter contained in the first recess and to transmit light to be received by the light receiver contained in the second recess; and a ground conductor layer located on a surface of the lid facing the first recess and the second recess and connectable to a ground potential, the ground conductor layer having a first opening configured to allow passage of light emitted from the light emitter, and a second opening configured to allow passage of light to be received by the light receiver, the ground conductor layer being electrically connectable to the one or more ground via conductors. a substrate including a substrate body including a plurality of dielectric layers stacked on one another, the substrate body being a rectangular plate and including a first recess and a second recess on a first surface thereof, the first recess being configured to contain a light emitter, the second recess being configured to contain a light receiver, and one or more ground via conductors located outward from the first recess and the second recess included in the substrate body in a plan view, the one or more ground via conductors being connectable to a ground potential; a substrate body including a plurality of dielectric layers stacked on one another, the substrate body being a rectangular plate and including a first recess and a second recess on a first surface thereof, the first recess being configured to contain a light emitter, the second recess being configured to contain a light receiver, and one or more ground via conductors located outward from the first recess and the second recess included in the substrate body in a plan view, the one or more ground via conductors being connectable to a ground potential; a lid being a plate covering the first recess and the second recess, the lid comprising an insulating material, the lid being configured to be put in contact with a body part and being configured to transmit light emitted from the light emitter contained in the first recess and to transmit light to be received by the light receiver contained in the second recess; and a ground conductor layer located on a surface of the lid facing the first recess and the second recess and connectable to a ground potential, the ground conductor layer having a first opening configured to allow passage of light emitted from the light emitter, and a second opening configured to allow passage of light to be received by the light receiver, the ground conductor layer being electrically connectable to the one or more ground via conductors.