[en] The Bethe-Salpeter equation in the ladder approximation of of the lambda phi³ theory for forescattering amplitude with the massive exchange is investigated. Solved are equations in a deep inelastic (Bjerken) region for small and large values of the exchanged mass. The solutions obtained have a scale-invariant form explicitly. Amplitude asymptote in the Redge-Bjerken region has a power nature. Work results permit to draw a conclusion, that scale invariance of the amplitude in the lambda phi³ theory conserves in all the range of exchanged mass values and, therefore, the exchanged mass effects insignificantly on scaling properties of the amplitude in the Bjerken region