The 94-year-old man, who had underlying health conditions, was a resident at Woodland Residential Care Home in Morda. He was taken into hospital on March 23 and died two days later.
Now boss Karen Williams and her staff are worried that more residents could die because old people's homes are being left "last on the food chain" for tests.
She said: "I'm quite disgusted by how old people are being treated. It make me so cross. They should be treated properly, not just left to die.
"We need more testing for the residents and the staff. My girls are working so hard. Some are working seven days a week because some are self-isolating. They are doing a fantastic job and we're trying to keep morale up.
"If we had testing, people could be isolated and we could stop the spread. The virus has been here so surely we should be a priority."
Last week Health Secretary Matt Hancock announced that testing would be ramped up, with a target of 100,000 a day by the end of April. Hospital patients and NHS staff have been top priority for testing, according to the government.
But Karen believes tests aren't coming quick enough for people living and working at care homes.
She said: "We started our lockdown two weeks before everyone else. I was shocked that it could get in. The handwash is here and everyone has masks and protective equipment. We've got everything in place, but we don't have testing.
"We had ambulances called out quite a lot last week. A lady is in hospital with pneumonia at the moment and we're waiting to see if it's Covid-19."
She added: "The man who died stayed in his bedroom and never came out. He showed symptoms then was taken to hospital the next day.
"He was a very poorly man, but he was the heart of Woodland. We looked after his wife before him. He was always smiling.
"The residents are scared. We're going round with masks on and they can't hear what we're saying.
"We've had the virus here. Staff are still going home to their families. How can anyone know if they are carrying it or not without testing?
"People here could be carrying it but showing no symptoms. We are last on the food chain to get testing."