  We propose an experiment to search for a new gauge boson, A$^\prime$, in
$e^+e^-$ annihilation by means of a positron beam incident on a gas hydrogen
target internal to the VEPP-3 storage ring. The search method is based on a
missing mass spectra in the reaction $e^+e^-\rightarrow \gamma$ A$^\prime$. It
allows observation of the A$^\prime$ signal independently of its decay modes
and life time. The projected result of this experiment corresponds to an upper
limit on the square of coupling constant $|f_{e\text{A}{^\prime}}|^2=1\cdot
10^{-8}$ with a signal-to-noise ratio of five to one at an A$^\prime$ mass of
15 MeV.
