  We perform estimation of critical exponents via large mass expansion under
crucial help of delta-expansion. We address to the three dimensional Ising
model at high temperature and estimate omega, the correction-to-scaling
exponent, nu, eta and gamma in unbiased and self-contained manner. The results
read at the highest 25th order expansion omega=0.8002, nu=0.6295, eta=0.0369
and gamma=1.2357. Estimation biased by omega=0.84(4) is also performed and
proved to be in agreement with the summary of recent literatures.
