You could use the Page Theme module to achieve exactly that :
The Page Theme module is a simple and easy module to use which allows to use different themes than the site default on specific pages.
Features :
Assign a theme to a single page or list of pages. (Set a page as a Drupal path)
Allow to use '*' character as a wildcard in Drupal paths.
Allow to arrange themes. (If pages are several defined, the first theme in the list will be used)
Allow to enable/disable a theme.
Drupal novice friendly.
as will as you can use :
Sections which has most of the same features as Page Theme, but adds a role based selection and a "php snippet" area to choose the theme.
but if you want to use different themes than the site default on content creating, editing, and viewing pages you can use
Content Theme which allows to use different themes than the site default on content creating, editing, and viewing pages.