Is there any API available from Monster for searching job
As of the date that this question was initially asked, they did not have a public API.
At that point, there were Yahoo Pipes that use their RSS feed, though.
Here's a site that generates links to RSS feeds on Monster.com, since it doesn't seem like there are regular RSS links available after you do a search, as there are on Indeed & SimplyHired..
As of the initial date of posting, it may have been possible to generate RSS feed links through the advanced search feature on Monster.com, but only if you have an account, since then you can save searches. This was described in How to Use Monster to Find a Job.
See the answer by Pedro Pereira, below. It appears that they may have an API as of 2013.
For more on that, you could research their documentation.
There seems to be one. Check their soap box at: http://integrations.monster.com/Toolkit/RealtimePosting/Sample/Inventory_Query/Jobs_All for an example on how to view all jobs. There is also a request JobPosting info http://integrations.monster.com/Toolkit/RealtimePosting/Sample/Queries/Get_JobPostingInfo . With a combination you could get jobs and info I guess.