PROBLEM TO BE SOLVED: To provide a process for production of ketones and aldehydes in which β-hydroxyhydroperoxides are processed with specific compounds.SOLUTION: General formula (2) (wherein, R, R, and Rare the same or different and each independently denote an alkyl group or the like. Rand R, Rand R, or Rand Rmay be combined together to form a ring structure) describes β-hydroxyhydroperoxides. This invention provides a process for producing ketones and aldehydes in which the β-hydroxyhydroperoxides are decomposed by reacting at least one compound selected from the group consisting of group Va element compounds, group VIIa element compounds, group VIII element compounds, group Ib element compounds, group IIb element compounds, group IIIb element compounds, group IVb element compounds, group Vb element compounds and lanthanide element compounds, with the β-hydroxyhydroperoxides.