To provide a sensing device and a sensing method that, by a simple method of liquid supply to first and second excitation electrodes, makes it possible to make a first oscillation area adsorb an adsorption substance that adsorbs a substance to be sensed in a sample solution and a blocking substance that prevents the adsorption of a substance and to make the electrode in a second oscillation area adsorb the blocking substance. By the supply of a solution containing the adsorption substance to a first liquid storage space 53A surrounding a first excitation electrode 42A, a front surface of the excitation electrode 42A is made to adsorb the adsorption substance, and next, by the supply of a solution containing the blocking substance to the first liquid storage space 53A, an area, of the excitation electrode 42A, on which the adsorption substance is not adsorbed, is made to adsorb the blocking substance. Further, by the supply of the solution containing the blocking substance to a second liquid storage space 53B separated from the first liquid storage space and surrounding a second excitation electrode 42B, a front surface of the second excitation electrode 42B is made to adsorb the blocking substance.