Communicated by M. LachowiczThis paper is devoted to obtain ladder inequalities for 2D micropolar fluid equations on a periodic domain Q = (0,L) 2 . The ladder inequalities are differential inequalities that connect the evolution of L 2 norms of derivatives of order N with the evolution of the L 2 norms of derivatives of other (usually lower) order. Moreover, we find (with slight assumption on external fields) long-time upper bounds on the L 2 norms of derivatives of every order, which implies that a global attractor is made up from C ∞ functions.