A biosensor comprising: a substrate having a rigidity K expressed by following formula, the rigidity K of the substrate being 3.0 N·mm 2 or less, the substrate including: a support layer that configures a first main surface of the substrate and a pressure-sensitive adhesive layer that configures a second main surface, opposite to the first main surface, of the substrate, and wherein the support layer is provided on the pressure-sensitive adhesive layer in the thickness direction of the biosensor; a component provided on the first main surface of the substrate, the component having a rigidity that satisfies following formula and is equal to or greater than a predetermined value, wherein the component includes a surface-mounted component provided on the substrate; and the surface mounted-component includes a plurality of electrodes, wherein each of the electrodes is embedded in the substrate such that an electrode surface is exposed at the second main surface, wherein K = ET 3 / 12 K ≦ 6.34 × 10 14 × S − 10.6 where E and T in formula denote a compressive elastic modulus at 23 °C expressed in megapascals (MPa), and a thickness expressed in millimeters (mm), respectively, and in formula, K denotes the rigidity expressed by formula in newton millimeters squared (N·mm 2), and S denotes a planar area expressed in square centimeters (cm 2), and wherein wherein the component includes the surface-mounted component and a sealing component configured to cover the surface-mounted component, the surface-mounted component and the sealing component satisfy the following formula and K ≤ 2.97 × 10 8 × S − 7.39 K ≧ 325 × S − 5 a substrate having a rigidity K expressed by following formula, the rigidity K of the substrate being 3.0 N·mm 2 or less, the substrate including: a support layer that configures a first main surface of the substrate and a pressure-sensitive adhesive layer that configures a second main surface, opposite to the first main surface, of the substrate, and wherein the support layer is provided on the pressure-sensitive adhesive layer in the thickness direction of the biosensor; a support layer that configures a first main surface of the substrate and a pressure-sensitive adhesive layer that configures a second main surface, opposite to the first main surface, of the substrate, and wherein the support layer is provided on the pressure-sensitive adhesive layer in the thickness direction of the biosensor; a component provided on the first main surface of the substrate, the component having a rigidity that satisfies following formula and is equal to or greater than a predetermined value, wherein the component includes a surface-mounted component provided on the substrate; and the surface mounted-component includes a plurality of electrodes, wherein each of the electrodes is embedded in the substrate such that an electrode surface is exposed at the second main surface, wherein K = ET 3 / 12 K ≦ 6.34 × 10 14 × S − 10.6 where E and T in formula denote a compressive elastic modulus at 23 °C expressed in megapascals (MPa), and a thickness expressed in millimeters (mm), respectively, and in formula, K denotes the rigidity expressed by formula in newton millimeters squared (N·mm 2), and S denotes a planar area expressed in square centimeters (cm 2), and wherein wherein the component includes the surface-mounted component and a sealing component configured to cover the surface-mounted component, a surface-mounted component provided on the substrate; and the surface mounted-component includes a plurality of electrodes, wherein each of the electrodes is embedded in the substrate such that an electrode surface is exposed at the second main surface, wherein K = ET 3 / 12 K ≦ 6.34 × 10 14 × S − 10.6 where E and T in formula denote a compressive elastic modulus at 23 °C expressed in megapascals (MPa), and a thickness expressed in millimeters (mm), respectively, and in formula, K denotes the rigidity expressed by formula in newton millimeters squared (N·mm 2), and S denotes a planar area expressed in square centimeters (cm 2), and wherein wherein the component includes the surface-mounted component and a sealing component configured to cover the surface-mounted component, the surface-mounted component and the sealing component satisfy the following formula and K ≤ 2.97 × 10 8 × S − 7.39 K ≧ 325 × S − 5