Proposed is dispensing technology capable of reliably spotting a
biological sample on a solid phase. A head chip applies a voltage pulse
between a diaphragm and separate electrodes based on a drive control
signal output from a head driver IC, and discharges a solution containing
protein filled in a pressurized chamber as a result of the elastic
deformation of the diaphragm. A drive pulse generation circuit generates
a drive voltage pulse and supplies this to the head chip in order to
discharge a solution containing protein from the head chip. The drive
current detection circuit detects a drive current flowing between the
diaphragm and separate electrodes. Since the waveform of the detected
drive current and the peak current value and so on differ in the case
where the discharge status is normal and in the case where it is
abnormal, a defective discharge can be discriminated by detecting such
change.