  The Planck constant, with its mathematical symbol $h$, is a fundamental
constant in quantum mechanics that is associated with the quantization of light
and matter. It is also of fundamental importance to metrology, such as the
definition of ohm and volt, and the latest definition of kilogram. One of the
first measurements to determine the Planck constant is based on the
photoelectric effect, however, the values thus obtained so far have exhibited a
large uncertainty. The accepted value of the Planck constant,
6.62607015$\times$10$^{-34}$ J$\cdot$s, is obtained from one of the most
precise methods, the Kibble balance, which involves quantum Hall effect,
Josephson effect and the use of the International Prototype of the Kilogram
(IPK) or its copies. Here we present a precise determination of the Planck
constant by modern photoemission spectroscopy technique. Through the direct use
of the Einstein's photoelectric equation, the Planck constant is determined by
measuring accurately the energy position of the gold Fermi level using light
sources with various photon wavelengths. The precision of the measured Planck
constant, 6.62610(13)$\times$10$^{-34}$ J$\cdot$s, is four to five orders of
magnitude improved from the previous photoelectric effect measurements. It has
rendered photoemission method to become one of the most accurate methods in
determining the Planck constant. We propose that this direct method of
photoemission spectroscopy has advantages and a potential to further increase
its measurement precision of the Planck constant to be comparable to the most
accurate methods that are available at present.
