Typology of microdevelopment of thinking regarded as a process of looking for a solution of a problem has been elaborated. The way the content of the problem is understood determines peculiarities of the control over the process; at that the process is mediated by particular operations of manipulation with elements of the content. Four levels of control are described - on the basis a) of situational understanding, b) of the general principle of solution of problems, c) of understanding specific principles of solution, d) of understanding the interrelations between the general and specific principles. Three levels of mediation are presented: manipulation with material objects (a), with their images (b) and denotations (c). A table is given which includes 60 types of thought's microdevelopment at different levels of control and mediation. It is shown how the concept of the "microdevelopment type" can be applied to a number of problems in the psychology of thinking.