The construction of a compact, transportable, and multipurpose high-pressure unit consisting of a pressure generating system and a four-window optical UV–VIS high-pressure cell for spectroscopic measurements at pressures up to 200 MPa is described. The pressure generating system can be operated with a wide range of liquids suitable as pressurizing medium. The optical cell can be used for spectroscopic and kinetic (flash photolysis and laser induced T-jump) measurements.