A work object processing apparatus includes: a message thread processing unit configured to be displayed through a chat room of an Internet messenger associated with a message thread, to receive a work object including a work producer, a work processor, and work contents, and to process a work object operation on the message thread; and a work object processing unit configured to process a work object state of the work object changed, from among a plurality of work object states of the work object included in a work processing diagram, based on a work interaction between the work producer and the work processor.