Micro-explanation is the explanation of the behaviour of macro-systems in terms of the behaviour of their micro-constituents. As elaborated in Chapter 1 its success is taken by microphysicalists to provide an argument for micro-determination, micro-government and micro-causation. In the first part of the present chapter I will distinguish various kinds of microexplanation, in particular those that pertain to the part-whole relation from those that concern the relation of two properties of the same system. Given that micro-explanation is taken to support (micro)physicalism it is important to disentangle these forms of explanation. Whereas micro-explanation concerning the part-whole relation ought to be taken to provide evidence for microphysicalism, micro-explanation that relates two properties of the same system may be taken to lend support to identity-physicalism. Running together different forms of micro-explanation seems to be one of the reasons for the failure to distinguish microphysicalism and identity-physicalism.