Ashley Yates placed the device in the toilets of The Tynings Primary School in Staple Hill, South Gloucestershire, and recorded images.
Yates, 45, admitted making indecent images of children and voyeurism at Bristol Crown Court.
South Gloucestershire Council said it was supporting pupils, parents and staff.
The court heard Yates, of Filton, who is married with children, filmed six girls, one boy and two members of staff.
A South Gloucestershire Council spokesperson said: "Ashley Yates remains suspended from the Tynings Primary School and while the police investigation is under way it would be inappropriate to comment further at this time.
"We are continuing to work closely with the school to ensure that pupils, parents and staff are being supported."
The Nation Union of Teachers (NUT) is also offering legal and emotional support to those affected.
South Gloucestershire NUT President Kerry-Anne Barber said statutory safeguarding policies "have been adopted to protect our young people and staff from incidents such as these".
"Unfortunately, in this isolated case, a rogue head teacher has breached these high safeguarding standards with extremely serious ramifications for the children and staff at The Tynings Primary School," she said.
Yates pleaded guilty to three separate counts of making indecent images of children and two separate counts of voyeurism.
He will be sentenced on 9 August and remains in custody.
The court heard he had handed over passwords to computers which would assist with the continuing police investigation.
A psychiatric report is being prepared.
A "rogue" primary school head teacher used a spy pen to film pupils and staff in the toilets at his school.