Sensor apparatus for measuring moisture, consisting of an electrically conductive semiconductor carrier substrate (1; 11; 111; 211), having - a capacitive moisture sensor arranged thereon that comprises a base electrode (3; 13; 113; 213), a moisture-permeable top electrode (5; 15; 115; 215) and a moisture-sensitive dielectric (4; 14; 114; 214) arranged between the base and top electrodes (3, 13, 113, 213; 5, 15, 115, 215), and - at least one reference capacitance (C_REF; C_REF1; C_REF2) arranged thereon for evaluating the moisture sensor, - wherein the base electrode (3; 13; 113; 213) of the capacitive moisture sensor is furthermore part of the at least one reference capacitance (C_REF; C_REF1; C_REF2), - wherein on the semiconductor carrier substrate (1; 11; 111; 211) a passivation layer (2; 12; 112; 212) is arranged, to which the base electrode (3; 13; 113; 213) is applied, and multiple contact-connection terminals (GE1; DE1; CR1; 10.1 - 10.4) are formed for connection to a moisture measurement circuit arrangement, in particular at least one contact-connection terminal (DE1; 10.3) for the top electrode (5; 15; 115; 215), at least one contact-connection terminal (GE1; 10.4) for the base electrode (3; 13; 113; 213) and at least one contact-connection terminal (CR1; 10.1; 10.2) for the semiconductor carrier substrate (1; 11; 111; 211), and - wherein the reference capacitance (C_REF; C_REF1; C_REF2) comprises the base electrode (3; 13; 113; 213), the semiconductor carrier substrate (1; 11; 111; 211) and the passivation layer (2; 12; 112; 212), and - wherein the moisture sensor and the reference capacitance (C_REF; C_REF1; C_REF2) are arranged above one another. - a capacitive moisture sensor arranged thereon that comprises a base electrode (3; 13; 113; 213), a moisture-permeable top electrode (5; 15; 115; 215) and a moisture-sensitive dielectric (4; 14; 114; 214) arranged between the base and top electrodes (3, 13, 113, 213; 5, 15, 115, 215), and - at least one reference capacitance (C_REF; C_REF1; C_REF2) arranged thereon for evaluating the moisture sensor, - wherein the base electrode (3; 13; 113; 213) of the capacitive moisture sensor is furthermore part of the at least one reference capacitance (C_REF; C_REF1; C_REF2), - wherein on the semiconductor carrier substrate (1; 11; 111; 211) a passivation layer (2; 12; 112; 212) is arranged, to which the base electrode (3; 13; 113; 213) is applied, and multiple contact-connection terminals (GE1; DE1; CR1; 10.1 - 10.4) are formed for connection to a moisture measurement circuit arrangement, in particular at least one contact-connection terminal (DE1; 10.3) for the top electrode (5; 15; 115; 215), at least one contact-connection terminal (GE1; 10.4) for the base electrode (3; 13; 113; 213) and at least one contact-connection terminal (CR1; 10.1; 10.2) for the semiconductor carrier substrate (1; 11; 111; 211), and a passivation layer (2; 12; 112; 212) is arranged, to which the base electrode (3; 13; 113; 213) is applied, and multiple contact-connection terminals (GE1; DE1; CR1; 10.1 - 10.4) are formed for connection to a moisture measurement circuit arrangement, in particular at least one contact-connection terminal (DE1; 10.3) for the top electrode (5; 15; 115; 215), at least one contact-connection terminal (GE1; 10.4) for the base electrode (3; 13; 113; 213) and at least one contact-connection terminal (CR1; 10.1; 10.2) for the semiconductor carrier substrate (1; 11; 111; 211), and - wherein the reference capacitance (C_REF; C_REF1; C_REF2) comprises the base electrode (3; 13; 113; 213), the semiconductor carrier substrate (1; 11; 111; 211) and the passivation layer (2; 12; 112; 212), and - wherein the moisture sensor and the reference capacitance (C_REF; C_REF1; C_REF2) are arranged above one another.