We present a new-generation optical-resolution confocal photoacoustic microscope, consisting of a 0.25-numerical aperture optical microscope objective and a 75-MHz center-frequency spherically focused ultrasonic transducer. Experiments verified that this microscope has a transverse resolution of 2 microm, which is the highest to our knowledge among all photoacoustic imaging systems. In situ imaging of mouse ears shows the feasibility of resolving individual red blood cells in microvessels using the current system.