  A mechanism of self-heating of solar corona is pointed out. It is shown that
the free energy available in the form of sheared flows gives rise to unstable
electrostatic waves which accelerate the particles and heat them. The
electrostatic perturbations take place through two processes (a) by purely
growing sheared flow-driven instability and (b) by sheared flow-driven drift
waves. These processes occur throughout the corona and hence the self-heating
is very important in this plasma. These instabilities can give rise to local
electrostatic potentials $\varphi$ of the order of about 100 volts or less
within $3\times10^{-2}$ to a few seconds time if the initial perturbation is
assumed to be about one percent that is $\frac{e\varphi}{T_{e}}\simeq10^{-2}$.
The components of wave lengths in the direction perpendicular to external
magnetic field $\textbf{B}_{0}$ vary from about 10m to 1m. The purely growing
instability creates electrostatic fields by sheared flows even if the density
gradient does not exist whereas the density gradient is crucial for the
concurrence of drift wave instability. Subject headings: Sun: self-heating of
corona, sheared flow-driven instability, drift waves.
