In a mechanical pencil capable of double-chuck and side-knock type lead control functions, a slide member is axially slidably fitted in a barrel fixedly provided at its front end with a head cap, a knocking member is pivotally supported in an opening formed in the barrel to operate the slide member so that a lead projecting back chuck on which a chuck ring is loosely fitted is advanced against the resilience of a chuck spring biasing the lead projecting back chuck backward to project a lead, a sleeve is fitted on the back chuck, an inner barrel is fitted on the sleeve, and a lead holding front chuck is placed in the head cap and is biased backward by a spring.