The stability at temperature approaching to zero and finite temperature of thin, gas pressure dominated accretion disk around neutron star is presented in this book. The contribution of both fully and partially degenerate electrons for the stability of the disk in middle and outer regions are investigated. Moreover, the book provides different regions of the disk where gas pressure is more dominant than radiation pressure.An accretion disk is a structure formed by diffuse material in orbital motion around a central body,like a neutron star. The aim of this book is to serve as a reference in order to understand the contribution of non-relativistic degenerate electron pressure to the stability of thin Keplerian accretion disks around a neutron star.