The aim of the study is to examine the character of the influence of automatic fiscal policy instruments on the shaping of internal stabilization of the market economy, where this stabilization involves limitation of the amplitude of business fluctuations, reduction of unemployment and restraint of the dynamics of inflation processes. The paper consists of an introduction, three parts and a conclusion. In the first part, after introductory remarks, hypotheses were formulated as concerns goals and role of automatic fiscal policy instruments in the process of stabilizing market economies. The second part presents evolution of tax fiscal instruments applied in Poland and ponders upon the question whether their influence is automatic or discretionary. The subsequent part contains the results of empirical analyses, showing the impact of automatically applied direct taxes on accomplishment of the goals of internal stabilization of Poland’s economy in the period from quarter I 2000 to quarter III 2014.