The invention provides an aliphatic polymer having a ketone group and ether bonding in its main chain, characterized by comprising structural units represented by the Formula (1) and by the Formula (2). In the Formulae (1) and (2), Ra and Rb each independently represents a substituted or unsubstituted divalent aliphatic hydrocarbon group. Rc represents a substituted or unsubstituted divalent aliphatic hydrocarbon group having ether bonding in a terminal thereof, or a single bond. n1 represents an integer of 1 or more. n2 represents an integer of 0 or more. And, n1+n2 is in a range of 2 to 1000. The polymer preferably contains ether bonds and ketone groups in a ratio of 0.01 to 100. The polymer can be substantially comprised of a structural unit represented by the Formula (1) as a repeating unit. A resin composition containing as a component structural units represented by the Formula (1) is also provided. The resin composition may further comprise an electrically conductive powder.