The energy firm Cuadrilla started the process at a site in Lancashire despite attempts by protesters to blockade the site.
It is the first time fracking has taken place in the United Kingdom since 2011, when the nascent industry was halted after it caused two small earthquakes in Lancashire.
"Those that protest against shale gas maintain that it has no "social licence to operate" and the that Government is forcing it through at the expense of local democracy". Demonstrators say they'll monitor the site around the clock. It is definitely not over, it has just got serious.
Ms Evans said the there was a mood of disappointment among protesters, and added: "I'm gutted really".
"There is so much more if this goes then everywhere is up for grabs, basically about the only place that won't be being drilled is under the Houses of Parliament", she added.
One activist sat on top of a van outside the site with a banner which read "Stop the Start" while another lay down in front of railings. "It's such a risky industry and it shouldn't be here".
Justin Vanparys, 47, from Blackburn, said: "Fossil fuels should stay in the ground".
It followed an environmental campaigner failing in a bid to halt the work at the High Court on Friday. The company had planned to restart its fracking activity as early as Saturday, but was prevented from doing so by the disruption caused by Storm Callum. The firm was expected to begin fracking, to release shale gas, at around 8am today.
Cuadrilla will force water, sand and chemicals down a well to hydraulically fracture rock about 1.5 miles below the surface. We are now commencing the final operational phase to evaluate the commercial potential for a new source of indigenous natural gas in Lancashire. In response to the IPCC's latest report on climate change and the action required, Perry said there was "no excuse" for failing to act, a statement that has prompted claims of hypocrisy from those opposed to fracking.
The government asked its climate advisers on Monday to examine whether Britain should toughen its climate targets and set a date to move to a net zero emissions goal.