This paper presents a numerical stable solution of one inverse plasma physics problem. To reconstruct plasma-electron energy distribution function, which is one of the principle characteristics of high temperature plasma, the first kind Fredholm integral equation can be solved. The equation connects the unknown function with the bremsstrahlung spectrum, that can be measured experimentally. The problem is unstable relatively to the errors in the initial data. To obtain a stable numerical solution, the Tikhonov regularization technique and discrepancy principle can be applied. Usually, the Tikhonov functional is considered with stabilizers of the first or second kind, in this paper, however, the functional with linear combination of two stabilizers was built. Thus, we were able to reconstruct plasma-electron energy distribution more accurately.