An information processing apparatus comprising: an attribute value acquisition means arranged to, while a user is inputting a search word in a state in which the user has selected a search object category, acquire, from a category information database that stores an attribute name and an attribute value of an attribute corresponding to each of a plurality of search object categories in association with each other, an attribute value suitable for the search word that is being inputted, the attribute value being acquired from among attribute values associated, in the category information database, with the search object category selected by the user; a presentation control means arranged to cause a combination of the attribute value acquired by the attribute value acquisition means and an attribute name of the attribute value to be presented in a proposal area on a user terminal as a candidate for a search condition for selection by the user, wherein, the information processing apparatus is arranged to receive a search request from the user terminal when the user selects the combination of the attribute value acquired by the attribute value acquisition means and the attribute name of the attribute value, the search request including a category ID of the selected category, an attribute ID corresponding to the selected attribute name, and the attribute value, and the information processing apparatus comprises: an object search means arranged, in response to receipt of the search request, to search, in a search object information database, search object information belonging to a category indicated by the category ID, for search object information having an attribute name indicated by the attribute ID and having an attribute value the same as the attribute value indicated in the search request. an attribute value acquisition means arranged to, while a user is inputting a search word in a state in which the user has selected a search object category, acquire, from a category information database that stores an attribute name and an attribute value of an attribute corresponding to each of a plurality of search object categories in association with each other, an attribute value suitable for the search word that is being inputted, the attribute value being acquired from among attribute values associated, in the category information database, with the search object category selected by the user; a presentation control means arranged to cause a combination of the attribute value acquired by the attribute value acquisition means and an attribute name of the attribute value to be presented in a proposal area on a user terminal as a candidate for a search condition for selection by the user, wherein, the information processing apparatus is arranged to receive a search request from the user terminal when the user selects the combination of the attribute value acquired by the attribute value acquisition means and the attribute name of the attribute value, the search request including a category ID of the selected category, an attribute ID corresponding to the selected attribute name, and the attribute value, and the information processing apparatus comprises: an object search means arranged, in response to receipt of the search request, to search, in a search object information database, search object information belonging to a category indicated by the category ID, for search object information having an attribute name indicated by the attribute ID and having an attribute value the same as the attribute value indicated in the search request.