Electrophysiological measuring apparatus which is configured for intracellular detection of at least one electrical measuring value on a biological cell sample, comprising - a substrate device configured to receive the cell sample, - an electrode device with at least one nanoelectrode which extends in a longitudinal direction in each case and can be introduced intracellularly into the cell sample which is received by the substrate device, and - an actuating device which is configured for moving of the at least one nanoelectrode and/or the cell sample relative to one another and along the longitudinal direction of the at least one nanoelectrode such that the at least one nanoelectrode penetrates into the cell sample, wherein - the actuating device comprises a suction device configured to draw the cell sample towards the at least one nanoelectrode, - the suction device comprises at least one suction opening (31, 34) in the substrate device and a pump device which is configured to apply a negative pressure to the at least one suction opening (31, 34), and - the at least one suction opening (31, 34) is shaped such that when the at least one suction opening (31, 34) is subjected to the negative pressure, the cell sample is moved along the longitudinal direction to the at least one nanoelectrode, characterized in that - a chamber with a chamber wall having a conical shape which narrows towards the substrate is provided above the substrate device, wherein the chamber is configured to receive a cultivation medium and the cell sample in the form of a cell aggregate, and - a projection for fixing the cell sample is provided above the substrate device in the chamber wall at the lower end of the chamber. - a substrate device configured to receive the cell sample, - an electrode device with at least one nanoelectrode which extends in a longitudinal direction in each case and can be introduced intracellularly into the cell sample which is received by the substrate device, and - an actuating device which is configured for moving of the at least one nanoelectrode and/or the cell sample relative to one another and along the longitudinal direction of the at least one nanoelectrode such that the at least one nanoelectrode penetrates into the cell sample, wherein - the actuating device comprises a suction device configured to draw the cell sample towards the at least one nanoelectrode, - the suction device comprises at least one suction opening (31, 34) in the substrate device and a pump device which is configured to apply a negative pressure to the at least one suction opening (31, 34), and - the at least one suction opening (31, 34) is shaped such that when the at least one suction opening (31, 34) is subjected to the negative pressure, the cell sample is moved along the longitudinal direction to the at least one nanoelectrode, - a chamber with a chamber wall having a conical shape which narrows towards the substrate is provided above the substrate device, wherein the chamber is configured to receive a cultivation medium and the cell sample in the form of a cell aggregate, and - a projection for fixing the cell sample is provided above the substrate device in the chamber wall at the lower end of the chamber.